camlost

[1.0.5] Advanced Jet Engine v2.6.1 - Feb 1

1627 posts in this topic

 

 

Advanced Jet Engine is a mod that provides realism for turbojet, turbofans, air-breathing rockets, propellers and rotors in KSP. If you're concerned with how real airplanes perform or you're a flight simulator fan, this mod is for you. The level of engine simulation rivals most commercial flight simulators..

 

KSP is a game that focuses on rocket and rocket engines, all other types of engine are modeled in a similar manner to rockets. As a result, two fundamental flaws exists. Given that FAR is used instead of the stock aerodynamics, these flaws render all jet engines unrealistically overpowered.

1.In reality, the thrust of a jet engine is proportional to the gas flow through the engine core. Thus at high altitude where air is thinner, the engine should have less power. However in KSP as long as you spam enough "intakes", the engines have the same power as at sea level. As a result, almost any airplane should be able to reach a high mach number when it climbs high and face less drag. Similar problems stand for propellers and rotors.

2.The intakeAir is counted as fuel. For the stock part 'turbofan engine', one unit of Liquid Fuel is burnt with 15 units of IntakeAir. So the actual engine efficiency would be 15 times more than what Isp tells. In other words, the actual Isp would be ~30,000s, a ridiculously high value.

 

 

 

For explanation of jet engine parameters and algorithm, go to https://github.com/camlost2/AJEsolverTester

The propeller code is based on JSBSim, with customization from NathanKell

Rotors use a simplified model by the author.

 

Features

 

 


  • [*=left]Real-world jet engines AJE uses thermodynamic equations to calculate jet engine performance in flight.
    [*=left]Real throttle Throttle is linked to fuel consumption instead of thrust. Afterburners, if installed on the engine, is turned on when throttle > 66% and off when throttle <= 66%
    [*=left]Overheat.Like in real world, not all engines can tolerate the heat from air compression of hypersonic flight. The effect is affected by speed not throttle.
    [*=left]Inlet.Each engine requires a minimum inlet area (see right click menu in editor). Make sure you have enough inlet till you see "Inlet Area:100%" in flight. Each inlet has a TPR(total recovery pressure) that is dependent on Mach number and angle of attack. Avoid TPR loss by facing the inlet to the freestream.
    [*=left]RealFuels support.Engines use Kerosene if

RealFuels is installed. RAPIER burns LqdMethane+LO2, SABRE burnes LH2+LO2.
[*=left]Mod friendly.Relatively easy to make configure for new engines and supporting many mods including B9,Firespitter,KAX,Taverius' Pizza,D12aerotech,SXT,RetroFuture,BahaMotoD'pack

 

 

 

 

 

Installation

Requires FAR

Recommend Real Airplanes by Genius Evil

 

 

 

 

Download from Github

 

AJE incorporates portions of NASA EngineSim; used according to NASA's license thereof with due credit. AJE incorporates portions of JSBSim by Jon S. Berndt, used in accordance with the LGPLv2

License is LGPL v2

 

 

Changelog

2.6.1
Fix an issue that was causing the black screen bug on rotors when they throttled down to zero.

2.6

  • SolverEngines 1.15
  • Fix node orientation on Merlins
  • Fix CF34 mass
  • Fix negative thrust bug finally: idle throttle set to give tailpipe pressure greater than ambient
    • Fan/compressor work now determined by proportional work rather than proportional pressure ratio
  • Fix duplicate solar panel issue with VSR
  • Remove RF fuel patches for multimode engines - those belong in other mods
  • Mass flow through jets now calculated based on choked turbine (reference: this book)
    • Reduces supersonic thrust growth a lot
  • Overhaul jet animations - should be much more consistent now
  • Minor adjustments to B9 config

2.5.4

Fix issue where Ramjet would have no model

2.5.3

  • Update Baha inlets with new cockpit
  • Update for SolverEngines engine fitting changes
  • Updates for Ven's Stock Revamp
  • Updates for B9 5.4.0
  • Update SolverEngines to 1.14

2.5.2

Update Metadata
 

2.5.1

 

  • Finish removing Kerosene and AvGas configs from jets and props. Now the only engines whose fuels are set are the SABREs and MkIVs, but they too will eventually get shifted over to an engine pack (RO, or RF Stockalike).
  • Update emissive patching to work in 1.0.5.
  • Change how stock clones' models are assigned: if Ven's Stock Revamp is installed, use VSR"s turboramjet model for some jets for variety. Even if VSR is installed, however, keep using the Squad 1.0.5 models for the J58 (TRJ) and CF34 (Wheesley).
  • Update to SolverEngines v1.13.
  • Ensure jets lose throttle when shut down.

 

2.5

 

  • KSP 1.0.5 compatibility
  • Update SolverEngines to 1.12
  • Add new Squad parts from 1.0.5
    • Correct existing parts for these changes, e.g. J85 is now Juno, Wheezley is now CF34, TRJ clones are now Panther clones, intake adjustments

     

    [*]Add underwater flameout condition to all engines

    [*]Adjust out-of-fuel logic for propellers

    [*]Separate out afterburner FX

     

    • spool effect now depends only on core throttle, power only on afterburner
    • More compatible with new stock separation of dry and wet engine modes
    • add spoolEffectName2 and powerEffectName2 with identical behavior to allow for multiple effects without SmokeScreen
    • Non-Squad engines have not had this updated yet. Effects may look wrong

     

    [*]New custom modules to handle heat and nozzle animations on jets

     

    • Thresholds may need tweaking
    • Not updated for non-Squad engines
    • Negative thrust bug causes weirdness on some engines, e.g. J58

     

    [*]Add J75 per Svm420's request

    [*]Make all part creation in squad config FOR[aaa_AJE]

     

    • Still needs to be done for others, namely B9

     

     

 

[h=3]Known issues[/h]

 

  • Negative thrust big is still present, quite visible on some engines
    • Causes nozzle weirdness on J58

     

    [*]Non-squad engines may have effects looking wrong due to changes

    [*]Squad engines might have bad effects with RealPlume or HotRockets

     

 

2.4.1

 

  • Update Solver Engines to v1.11.
  • Update how jet engines create heat for KSP thermo (they will no longer be furnaces).
  • Fix DB 605 description.

 

2.4.0

 

  • Propellers now produce correct amount of thrust, thanks ferram4
  • Fix Meredith effect, exhaust thrust, not applying cooler efficiency or cooler min, calcing boost pressures for MAP, magneto perma-off-prop bug (ferram4)
  • Adjust Stock Revamp MM syntax
  • Fix F404 Wet Thrust
  • Add DB-605A
  • Convert J57, J79, Atar, Avon to clones of stock TRJ instead of B9 turbojet - will be moved to clones of Panther in KSP 1.1
  • Update SolverEngines to 1.10
    • Fixes propellers being unable to start after flameout
    • Adds temperature-based auto-restart on flameout: jets and non-electric props will only auto-restart if the internal temperature is above a certain threshold

     

     

 

v2.3.0 for KSP 1.0.4

Changes

 

  • Engine fitting enabled on all jet engines
    • Engine-parameters are auto-tuned to give correct thrust and sfc
    • Fitting is re-done when config changes are detected or plugins change

     

    [*]Jet engine core rewritten with new thermodynamics

    [*]Jet engine nozzles reworked somewhat

     

    • Added adjustableNozzle field to prevent subsonic jets from creating supersonic exhaust. It doesn't enable a true fixed area nozzle, but results are better - no massive thrust growth on airliner engines
    • Supersonic jets no longer get choked nozzle pressure bonus.
    • Various corrections to nozzle thermodynamics

     

    [*]Add areaFudgeFactor field to jets in order to match intake and engine area in sensible way. Defaults to 0.75

    [*]Correct afterburner effects on many engines so that they engage when they should

    [*]Add rescaled pylons for rescaled B9 podded jets

    [*]Support/remove intakes on stock engine bodies

    [*]Insufficient intake area now cuts intake pressure rather than thrust - will efficiency as well

    [*]Only create rescaled engines if ProceduralParts is present. A few tweaked to stock scales in absence of PP

    [*]Use turbojet model for F100 and F404 if VenStockRevamp is present - it's a more correct model

    [*]Mod support updates for MarkIV System, BahamutoDynamics, and QuizTechAero

    [*]Engines auto-restart after flameout once fuel is available again.

    [*]Various engine parameter tweaks

    [*]Various wildcard fixes

     

 

Known issues

 

  • Propellers are effectively broken right now - issues will be looked at in coming days
    • They do not produce as much thrust as they should
    • Some will not start
    • They cannot be restarted after flameout (or possibly throttle to zero)

     

    [*]Some engines can show negative thrust at low throttle/TPR

     

 

v2.2.1

Finished updating jet configs to new module (ModuleEnginesAJEJet)

Finished updating inlet configs to read TPR curves from templates

Adjust TPR curves to be smoother (previously tangents were zero everywhere - see #26 which this fixes)

Update SolverEngines to 1.4

Recompile for KSP 1.0.4 and SolverEngines 1.4

v2.2.0

Stable release for KSP 1.0.2.

v2.0.4

Recompiled with latest FAR version

Fix: sound effect sometimes not responding to throttle

Fix: B9 SABRE M max thrust

Mod support: QuizTechAero, MarkIVSystem

Misc compatibility fix

v2.0.3

Avoid quick overheating when DRE is installed

Minor change in ram drag calculation

Avoid the issue where piston engines cannot start at 0 throttle

v2.0.2

Recompiled for FAR 0.14.6

Remove minimum throttle

Avoid engine flaming out on the runway

Part title cleanup

v2.0.1

Fix a bug in inlet area calculation

v2.0

redo jet engine code

Improvements over the original program include:

0.Everthing in SI units

1.Simple off-design calculation of compressors

2.Real throttle

3.All engine is one type

4.An option to mix fan duct and core flow before the nozzle

v1.6.8

Recompiled for FAR 0.14.4

Some engines from RetroFuture mod

Determine spool up time based on engine size

Heat code rewrite by NathanKell

Misc fix

v1.6.4

RAPIER uses LqdMethane

SABRE M thrust fix

Added a stock ramjet

v1.6.4

RetroFuture engine & inlets (partial)

cfg cleanup & Misc. bug fix

v1.6.3

Fixed compatibility without RF

v1.6.2

Use JSBProp by NathanKell for propellers.

Changed definition of B9 tubofans

SABRE and RAPIER work better without RF

Ignore heatProduction if DRE is installed

Misc fix

v1.6

0.25 compatibility

tweaked the inlet code suggested by virandi

more engines and bug fixes

v1.5

Backports from NathanKell's fork:

*Redone piston engine support (inter/aftercoolers, multiple speed/stage superchargers,

volumetric efficiency, ram air, and real performance for the included piston engines)

*Jets show gross thrust as well as net thrust

*Some intake area tweaks (still needs work to get sqft area of each intake part

*Ported over all real jets and piston engines from RftS.

*All included jets should perform like their real counterparts now. Real stats were used

when available, educated guesses made when not.

*Cleaning and variable-renaming in the EngineSim code for clarity and understanding

*Update to 0.24.2 and FAR 0.14.1.1

*Seamlessly works with or without RealFuels

Fixes from taniwha to the DA (TVPP) engines and intakes.

v1.4

. .Fixed some inlet data

. .In-editor information of inlets and engines

. .Added some engines and inlets

. .Incorporated RftS textures for some B9 engines

v1.3

. .Inlets

. .A few more engines

. .Added support for RAPIER, tweaked SABRE

. .many DLL and CFG tweaks

v1.2

. .Engines have 3% idle thrust by default

. .Added TV_pizza support and several engines

v1.1.3

. .The propellers should work correctly on other planets(untested)

. .Added a new engine F404

v1.1.2

. .Solved compatibility issue with latest HotRocket

v1.1.1

. .Balanced propellers, added a speed buff

. .Support for KAX rotor wing

v1.1

. .Added *realistic* support for propellers and rotary wings

. .Supporting all FS and KAX propellers, including electric ones

. .Stock "turbojet" becomes J58 with "bleed air" feature, thanks to NathenKell, who provided a simple and elegant solution.

. .

v1.0

. .Combined everything into one module: AJEModule supports ME and MEFX at the same time

. .Using stock atmosphere pressure and temperature now, engines should have ~10% more thrust at high altitude

. .Engines have 10% more heat tolerance to compensate

. .AJE works without HotRockets now

v0.9

. .Fixed a bug with SABRE M

. .New afterburner logic

. .Upgraded J79 to J93, which is more powerful, especially for supersonic flight

v0.8

. .Added CoM Offset to stock, B9 and FS engines, making RL rip-off designing more easy.

. .Air intakes has no physical effect now. Jet engines don't require intakeair, but they still need an atmosphere with oxygen to work.

. .Compatibility support

 

 

FAQ

 

 

 


  • [*=left]My plane consumes fuel ridiculously fast. Fast yet realisticly rather than ridiculously. An F-16 that uses 1 x Pratt & Whitney F-100 has 3000 kg internal fuel, yet only lasts for minutes with full afterburner on. To see your airplane fly longer, either carry more fuel, restrain from using afterburner, or climb higher to save fuel.

 

13 people like this

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Looks very interesting, if I could build a plane in KSP I would defently use. You know what? I'm going to DL anyway cause it looks that awesome...

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Looks very interesting, if I could build a plane in KSP I would defently use. You know what? I'm going to DL anyway cause it looks that awesome...

Please use FAR otherwise everything still feels awkward. Seriously.

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Please use FAR otherwise everything still feels awkward. Seriously.

Who would go w/o FAR?

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Woohoo!

I am happy not least because it means I *don't* have to do something like this (only mine would be worse) for RF. :)

Can we specify parameters ourselves yet? Or can you only pick from EngineSim's own models?

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Woohoo!

I am happy not least because it means I *don't* have to do something like this (only mine would be worse) for RF. :)

Can we specify parameters ourselves yet? Or can you only pick from EngineSim's own models?

Partly, there are like 50 obscurely named parameters in the original code and I'm not sure what is what. Right now a few parameters can be defined. More are coming as I make more engines.

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Is the heating model compatible with Deadly Reentry? Because this sounds like something that could work really well combined with Realism Overhaul, or even end up as a required mod for it someday.

I assume support for ramjets, scramjets, and precoolers works well with this too?

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Is the heating model compatible with Deadly Reentry? Because this sounds like something that could work really well combined with Realism Overhaul, or even end up as a required mod for it someday.

I assume support for ramjets, scramjets, and precoolers works well with this too?

This directly changes part temperature so DRE wont' have an effect.

There's one ramjet already. I think I can make something that mathematically equals precooled engine. I haven't thought about scramjets or pulse detonation yet, probably impossible.

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Is this compatible with the engine overheating at high speeds in the Interstellar mod? In other words, if I have both mods am I getting twice the overheating? And if so, is there a way to turn yours off?

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Is this compatible with the engine overheating at high speeds in the Interstellar mod? In other words, if I have both mods am I getting twice the overheating? And if so, is there a way to turn yours off?

Does KSPI change heat mechanics of stock and B9 parts? Even if it does, they will have both effects. Usually they don't happen at the same time, even if they happen at the same time, AJE will overwrite other mods as AJE manipulate part temperature directly.

I don't think turning off heating mechanism of AJE is a good idea, because in reality the compressor material and turbine material is a major limit of supersonic jet engine design. If the material can endure unlimited heat then all turbojet engines will fly at Mach 3. Try EngineSim itself and you can see how much more advanced its heat mechanism is, compared to what stock, DRE or KSPI has to offer. For example, the CF6 turbofan will overheat ~Mach 1, but F100 won't, because their compressors are made of different materials.

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Hmm, I installed this mod and all my parts disappeared. Anyone else run into this?

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Hmm, I installed this mod and all my parts disappeared. Anyone else run into this?

Could you be more specific? Did you install RealFuel v4.3? What happened? Could you get into VAB? Could you start another save?

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Could you be more specific? Did you install RealFuel v4.3? What happened? Could you get into VAB? Could you start another save?

I installed and loaded, I lost all my parts, I can get into all the buildings, yet to attempt a new save will try tomorrow.

Sub Folders still exist.

Completely disregard my stupidity, did not install real fuels

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Even if without RF you shouldn't lose all parts. But there seems to be one problem related to MM. Could you just delete MP_Nazari/MP_Nazari.cfg and everything should be fine

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Even if without RF you shouldn't lose all parts. But there seems to be one problem related to MM. Could you just delete MP_Nazari/MP_Nazari.cfg and everything should be fine

I installed RF and everything came back

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Updated SABRE support:

I tweaked the code to add a precooler that changes freestream temperature to 140k for SABRE. The air-breathing mode of the engine was treated like a low-CPR afterburning turbojet using hydrogen. The thrust curve and isp curve is *kind of* close to this paper

But after a brief test-flight the engine can hardly accelerate to Mach 5. Seems I either have to tweak the code in some other way or rewrite some code. SABRE is a rocket after all

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O dear, so many great mods and so little memory.

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O dear, so many great mods and so little memory.

Only this one uses minimal memory

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Are you accounting for the fact that in real life, Isp is based on the mass flow of fuel (and only fuel), but in KSP, Isp is based on the mass flow of all resources being used by the engine module? In stock KSP since the engines count the mass flow of air into the Isp calculations they end up being 16 times as efficient as they claim.

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Are you accounting for the fact that in real life, Isp is based on the mass flow of fuel (and only fuel), but in KSP, Isp is based on the mass flow of all resources being used by the engine module? In stock KSP since the engines count the mass flow of air into the Isp calculations they end up being 16 times as efficient as they claim.

I think RF corrects that. Anyway I checked the fuel flow and isp and they do match.

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The actual flow of kerosene or the fuel flow from the engine, which includes units of intake air? I'm not aware of RealFuels correcting that particular discrepancy either; it still runs things through the stock ModuleEngines code, and that's where the error occurs. The only way to fix it in the stock engine code is to set the Isp to 1/16 what it "should" be.

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The actual flow of kerosene or the fuel flow from the engine, which includes units of intake air? I'm not aware of RealFuels correcting that particular discrepancy either; it still runs things through the stock ModuleEngines code, and that's where the error occurs. The only way to fix it in the stock engine code is to set the Isp to 1/16 what it "should" be.

It should be easy enough with a plugin like this to change the atmosphere curve values which affect the internal engine performance to produce proper fuel consumption behaviour while maintaining the correct displayed values by manual setting the realIsp field.

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Will fix that soon

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It should be easy enough with a plugin like this to change the atmosphere curve values which affect the internal engine performance to produce proper fuel consumption behaviour while maintaining the correct displayed values by manual setting the realIsp field.

Seems there's a weird bug with ModuleEnginesFX, I tried to divide isp by 16 and setting

@RESOURCE_DEFINITION[intakeAir]:Final

{

@density = 0.0

}

Both ways the fuel flow are corrected, but both ways the thrust decreased by a factor of ~1.67. That's to say I set thrust=50kN and it shows thrust=~30kN.

I changed the density to any other values their's always a offset.

===============================================

Changed the density back to 0.001 and everything's fine. Will try to directly reduce fuel. This is just unbelievable

Edited by camlost

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The issue is that the air intakes aren't feeding enough air into the engine in both cases, which causes them to throttle down, since it's still above the flameout threshold. I suspect that it might just be that the intake's resource pool isn't capable of holding enough air, in which case it can be fixed by simply increasing the resource pool for all intakes.

And don't go with the solution of giving IntakeAir density = 0. ModuleResourceIntake uses the density of the air it's flying in and the density of the resource to determine how many units of the resource to create, so under that solution a single intake produces an infinite quantity of that resource. So engines are never able to run out of thrust at that point. :confused:

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